This invention relates to sealing devices and, more particularly, to a sealing system for doors which block out moisture and outside air from the interior of a building.
Effectively sealing moisture and outside air from the interior of the building is an age old problem which has plagued the building industry. A variety of diverse solutions have been proposed to solve the problem. Until now, storm doors have provided the only truly effective remedy. However, storm doors are relatively expensive and require additional installation and maintenance. Furthermore, purchasers of costly decorative front doors for their homes are not overly enthusiastic about covering them up with obtrusive looking storm doors. Hence, there has been a search for a single door sealing system which provides the required weather resistance, within the confines of reasonable manufacturing expenditures. Most known prior art single door sealing systems have not responded adequately to the challenge. It is important to note that there are two distinct considerations for a single door sealing system, one being the ability to block out the outside air, and the other being the ability to seal out moisture such as rain from the interior.
One of the most common problems that have confronted builders is the proper installation of doors. This requires considerable man-hours to insure that the frames and doors are precisely in square and properly aligned. However, even if the doors are initially properly installed, settling of the house often creates a gap between the threshold and the door thereby providing a direct opening into the house. U.S. Pat. No. 3,900,967 to Bursk et al and U.S. Pat. No. 3,273,287 to Pease, Jr. are representative of prior innovations attempting to solve this problem. These patents disclose adjustable sill and threshold assemblies by which the threshold may be raised or otherwise adjusted to provide a good fit between the door and the threshold to accomodate for settling. However, these attempts only partially solve the problem because they do not provide an adequate moisture seal. Even more importantly, they require the builder to return to the premises and adjust the threshold, much to the displeasure of both the builder and the anxious homeowner.
Still other attempts have been made to correct the problem of water seeping underneath the door and into the interior. This problem is so wide spread that the American Society of Testing Materials has established as Test No. E-331 a proposed standard for moisture resistance capabilities of doors and windows. In this test, the device must be capable of completely blocking out water for a period of 15 minutes at a relative pressure differential equivalent to that created by a 30 mile per hour wind. Very few of the commercially available doors have been capable of meeting this standard and those which have been successful require painstaking and time consuming detailed workmanship to install the door.
Some of the most ambitious attempts to solve the moisture problem are disclosed in U.S. Pat. No. 3,851,420 to Tibbetts, U.S. Pat. No. 3,032,839 to Miller, U.S. Pat. No. 2,129,381 to Oftedal et al, and U.S. Pat. No. 2,108,137 to Oftedal et al. Each of these prior art systems generally employ what is known in the trade as a weep for draining the water away from the door. However, the Miller and Oftedal constructions provide a direct air leak into the home which, in this day of energy conciousness, is taboo. Likewise, the Tibbetts system is also susceptible to a gap being created at the bottom of the door when the house settles. Further, the fibrous pile material used in Tibbetts for the jamb weatherstripping does not provide adequate blockage for preventing air or water from passing around the lower sides of the door. These weep type systems are often rendered ineffective when mud or other debris clogs the drainage passages. More importantly, even moderately high winds will render the known weep systems ineffective against water seepage.
Since each of the prior art door sealing systems rely upon tight interference fits between the bottom of the doors and the threshold, relatively high forces are required to open and close the door. Obviously, this can be a problem for children, the aged or the handicapped because they often lack the strength to operate the door. Similarly, because of the high opening and closing forces commonly needed, these door seals tend to wear out or tear, thus necessitating frequent replacement.